The suit was brought forward by the League of Women Voters of Illinois. Other challenges to redistricting are still pending.
The League of Women Voters says it's disappointed in the outcome of its case. Group president Jan Dorner says the League had a novel argument, that districts drawn to overwhelmingly favor one party deprive people of their free-speech rights.
"It's our right -- my right as a citizen -- to hear both a Republican and a Democratic point of view when candidates are campaigning in my area" Dorner said after the court's decision.
Meanwhile, Republicans are still challenging the new boundaries of Illinois' legislative districts. They say they were not included in creating the new maps, and that Democrats drew the boundaries to favor their candidates.
Two cases remain: one before the Illinois Supreme Court and one before the U-S Supreme Court. The Illinois case was filed just a month before the primary. The Illinois Supreme Court has asked for more information, but only on why the Republicans waited so long to bring the case. Both Republicans and Democrats have provided the Supreme Court with the information it asked for, and a decision could come at any time. Democrats have maintained that the redistricting process was fair.